The impact of foreign language caregiving on native language acquisition.

There is increasing interest in the influence of language input during children's early years. Over the first 3 years of life, children are highly sensitive to the quantity and quality of language input they receive. The focus of this study was on whether learning a different language in the early years affects the acquisition of English over the longer term. In this study, we investigated effects of foreign language (Hokkien) caregiving on the eventual acquisition of English as well as on memory traces of Hokkien. We sampled individuals who received foreign language caregiving in Hokkien during their early years either predominantly or in addition to English. Our control group had lifetime primary exposure to English. We compared the Hokkien- and English-only reared groups on phonological, semantic, and grammatical knowledge in English. We also compared the groups on memories for Hokkien tonal phonology and vocabulary. Overall, there were no statistically significant differences in performance in English tasks between groups, yet the Hokkien-reared group demonstrated selective learning advantages in reacquiring Hokkien tonal contrasts. Findings are discussed with reference to the effects of timing and language input on later language proficiency.